This invention is directed to improvements in ventilating systems of the type disclosed in U.S. Pat. Nos. 3,841,062 and 4,129,179, both assigned to the assignee of this invention. One purpose of the '062 patent was to extract grease and cooking vapors as they are produced, and to reduce their deposition on the interior walls of the ventilator. Although the system of the '062 patent has proven highly effective in use, it required upward lifting of water from a reservoir in the bottom and therefore a higher static pressure rating of the exhaust fan to agitate and lift the water up into the scrubbing chamber area; and further utilized a downwardly and forwardly extending lower wall which tended to create an entrapment area for grease. Moreover, exact adjustment of the air inlet baffle was necessary for suspension of the water in the air/exhaust stream for most efficient grease extraction.
Other representative patents of interest are U.S. Pat. Nos. 3,055,285 to Gaylord; 3,624,696 to Cohen et al; 3,731,462 to Costarella et al; 3,943,836 to Kuechler and 4,071,019 to King. Although these patents are of interest insofar as ventilator systems are concerned, none discloses a truly effective means for extraction of contaminants through the use of cold water for cooling the metal walls, reducing exhaust air temperatures, or the condensation of grease vapors through cooling by water droplets/mist. Among other problems, it has been found that the air inlet baffles could be mistakenly set too high so as to negate the required air flow velocity to cause agitation of the water bath resulting in minimal splashing effect and inadequate grease extraction.
It is desirable to provide a ventilator system in which the grease vapors and lint can be removed without a water reservoir or grease entrapment area at the bottom as well as to avoid accumulation on the interior walls of the ventilator and particularly to avoid baked-on grease deposits which will prevent water from absorbing heat from the walls of the ventilator. Furthermore, it is desirable to avoid the necessity of critical adjustment of an air inlet baffle to accommodate varying air volume flows. It is further desirable to provide a ventilator system which is capable of suspending the water in the exhaust air stream above the air inlet baffles by introducing water above the air inlet so that it is free to undergo gravity flow in sheet form downwardly into the path of the upwardly flowing airstream resulting in turbulent circular motion of the water across the substantial extent of the air inlet area independently of the exhaust air flow volume, within limits, and the positioning of the air inlet baffles.